Sewer gas and emanations from sewage and filth will not communicate typhoid fever directly, but the latter afford nutriment for the growth of the germ, and after becoming infected, may eventually come in contact with drinking water or food, and so prove dangerous. Improper care of discharges of excrement and urine--with the assistance of flies--are responsible for the enormous typhoid epidemics in military camps, so that in the late Spanish-American War one-fifth of all our soldiers in camp contracted the disease. In the upper layers of the soil typhoid germs may live for six months through frosts and thaws. The disease is preventable, and will probably be stamped out in time. In some of the most thickly populated cities in the world, as in Vienna, its occurrence is most infrequent, owing to intelligent sanitary control and pure water supply, while in the most salubrious country districts its inroads are the most serious and fatal through ignorance and carelessness. =Development.=--From eight to twenty-three days elapse from the time of entrance of typhoid germs into the body before the patient is taken sick. One attack usually protects one against another, but two or three attacks are not unheard of in the same person. =Symptoms.=--Typhoid fever is subject to infinite variations, and it will here be possible only to outline what may be called a typical case. In a work of this kind the preliminary symptoms are of most importance in warning one of the probability of an attack, so that the prospective patient can govern himself accordingly, as in no other disease is rest in bed of more value. Patients who persist in walking about with typhoid fever for the first week or so are most likely to die of the disease.